Atlas Obscura
Revere's Ship Mill (Mulino natante di Revere) in Revere, Italy
The first known ship mill was invented in 537 during the siege of Rome, when General Belisarius stopped the flour shortage in the city by "reversing" the principle of the mill and putting the first prototype on the Tiber River. The ship mill later was widespread all across Europe in less than 20 years. It was also developed in Iraq in the 10th century. The Po River in Italy is the longest and m…